Ringer system for telephone-exchanges.



No. 768,971. 'PATENTED JULY 5, 1904.

- T. 0. DRAKE.

RINGER SYSTEM EOE TELEPHONE EXCHANGES.

APPLICATION FILED APR. 14. 1903.

N0 MODEL. 2 SHEETSSHEET l.

AIIIIIIIMIII AlIlIllllllllllll No. 768,971- PATENTED JULY 5, 1904 T. G.DRAKE.

RINGER SYSTEM FOR TELEPHONE EXCHANGES.

APPLICATION FILED APILM, 1903.

2 SHEETS-SHEET 2.

N0 MODEL.

El i]- WI 5 E5: In'i fifi a .4 c/ A v UNITED STATES Patented July 5,1904.

PATENT OFFICE.

THOMAS C. DRAKE, OF MALTA, OHIO.

SPECIFICATION forming part of Letters Patent No. 763,971, dated uly 5,1904.

Application filed April 14, 1903. Serial No. 152,500. (No model.)

To all whom it may concern:

Be it known that I, THOMAS C. DRAKE, a citizen of the United States,residing at Malta, in the county of Morgan and State of Ohio,

have invented certain new and useful Im-- provements in Ringer Systemsfor Telephone- Exchanges, of which the following is a full, clear,concise, and exact description, reference being had to the accompanyingdrawings, forming a part of this specification.

My invention relates to means for ringing telephone-bells ontelephone-lines in which a direct-current type of relay, such as cut-offrelays in common battery systems, are con' nected in multiple or bridgewith the bellwinding, the object being to operate the bell and relaysimultaneously by means of the same current when calling a subscriber.

Before my invention it has been proposed to bridge a direct-current typeof relay with current will only vibrate the relay-armature and not holdit steady the contacts of the relay are not properly made to effectsatisfactory op.- eration and ringing. One method of operating suchcircuits has been to employ a pulsating current, which by its successionof impulses of one polarity through the relay will give more or lesssatisfactory operation; but this method requires a condenser in thecallbell circuit in order to convert the pulsating current into suitablealternating current for operating the polarized call-bell. According toanother method it is proposed to bridge a special alternating-currentrelay with the alternating-current call-bell, the relay and callbellbeing adapted to operate in multiple when ringing over the line-circuitwith an alternating-current generator. In accordance with this methodthe special relay has been designed to operate with either alternatingor direct currents, and the construction involved a massive armaturethat is withdrawn from the core of therelay-magnet by gravity. Theoperation of the armature is thus sluggish, and upon ringing through thesame with an alternating current the magnetic attraction for thearmature is only intermittent and each successive alternation willenergize the core to cause the same to grasp the armature before thearmature has had time to be with drawn upon the cessation of themagnetism due to the immediately-preceding alternation. During thepassage of a continuous current, however, the armature will be held upto the core, due to a constant magnetic attraction; but When alternatingcurrent energizes the relay winding the armature is held up by means ofthe intermittent magnetic attraction or pull, the pulsations of whichare too rapid to permit the armature to recede from the pole appreciablybetween the pulsations.

The object of my invention is to provide a simple and satisfactorymethod of energizing the call-bells and relays simultaneously, so thatthe call-bell will be rung and the relays armature held steadilyattracted by means of the same energizing-current.

Another object of my invention is to provide a system of ringing whichwill permit the use of the ordinary type of continuous or steady currentrelays in systems and circuits which heretofore required a specialalternating-current relay.

The object of my invention is attained by connecting an electricalgenerator of suitable current for ringing a polarized call-bellin serieswith an electrical generator of suitable current to energize and hold upthe armature of a common type of continuous or steady current relay.

, To more fully understand my invention, I have illustrated the same inthe accompanying drawings, in which- Figures 1 and 2 illustrate the gistof my invention in its preferred embodiment, wherein analternatingcurrent generator and a suitable direct or steady currentgenerator are connected in series and bridged with a continuous-currenttype of relay and a polarized call-bell of the usual type; and Figs. 3and 4 are diagrams of commercial switchboard-circuits with my inventionasssociated therewith.

Referring to Fig. 1, c is a polarized callbell, in series with which isa resistance 0, adapted to prevent excessive current from interferingwith the bells operation. A desirable way to accomplish the same resultis to wind the bell-coils with suitable resistancewire. A preferablemethod, however. is to place the call-bell in series with a condenser.The latter method is diagrammed in Fig. 2, Where b is a condenser inseries with the callbell 7), the condenser effectually preventing directcurrent from affecting the bells polarization and at the same timeallowing fiuctuating current set up by the ringing-genera tor to act onthe gong-sounding mechanism of the call-bell in a manner wellunderstood.

In Fig. 1, c is a line-circuit represented as a ground-return; but it isobvious that it may be a metallic circuit in so far as the principles ofmy invention are concerned. Bridged with the line and in multiple withthe call-bell cis a direct-current type of relay 0 This relay may beemployed to etface a line-signal, according to any of the well -knownmethods, or employed to connect the line-circuit and jack together, asis diagrammed in Figs. 3 and 4. A generator of suitable current tooperate the call-bell is represented at c A suitable source of direct orsteady current to actuate the relay 0 is represented at 0, the twogenerators being connected in series and bridged across the relay andcall-bell, as the diagram clearly indicates. In Fig. 2 the cir cuits arethe same as Fig. 1, except that the call-bell is grounded through acondenser instead of through a resistance. In practice the generator 0is preferably designed for twenty-cycle alternating current, this beinga standard for ringing telephone-bells, and the direct-current generatormay be the storage battery employed in common-battery telephoneexchanges. Although the electrical dimensions of the several devicesemployed are not of the essence of my invention and may be variedconsiderably, good results have been obtained with the call-bell b woundto one thousand ohms and the condenser Z) of two-microfarad capacity,the relay If wound to five hundred ohms, the alternating-currentgenerator U giving eighty volts and the di-. rect or steady currentgenerator 6" giving forty volts.

The characteristics of an ordinary alternating generator for operatingtelephone-bells are well understood. During the reversal of polarity orchange in the direction of current there will be no effective currentflowing to energize the relay at certain intervals of each cyclethat isto say, there is a period in each alternation where no current isgeneratedand when ringing through relays of usual construction withcurrent of this character the armature of the relay will retract manner.

from the pole of the magnet, to-be again attracted, however, when thecurrent-wave rises well toward maximum. This results in continuousfluttering and chattering of the relayarmature while ringing and willnot operate the contacts properly for maintaining the circuits closed.

Referring to Fig. 3, my invention is associated with a well-knownswitchboard-circuit. In this circuit a subscribers line extends in twolimbs f f to the central station, where the same are connected,respectively, with the movable contact members f which are adapted to beactuated by means of the electromagnetf' and retracted to normalcondition when the electromagnet is not energized. The aggregation ofthe elements fififhf' f, it". and if constitute a cut-off relay. Underthe normal condition of the cut-off relay contact member f rests againstback contact 7 and the other contact member, f, rests against backcontact f. Between the back contacts are connected a line-relayf inseries with an energizing-battery f which battery is adapted to actuatethe line-relay when the resistance across the line-circuit or betweenthe two limbs f f is diminished in any suitable manner, usually byconnecting a suitable telephone apparatus across the line for talkingpurposes. For the object of describing my invention I have shown twocall-bells g and g connected from either side of the line to ground.These bells may be wound to high resistance or placed in an equivalentcircuit or connected with a condenser in a well-known A line-connectionterminal or jack 71, is adapted to have the thimble it thereof groundedthrough the cut-off-relay Winding f* and the line-spring 7L thereofconnected with front contact [L3- The thimble it of the jack is alsoadapted to be connected with the f side of the line through frontcontact it and contact member and the line-spring 11. is .adapted to beconnected with the f side of the line through contact 7L3 and contactmember-f. There is a suitable call-plug z, connected throughcord-strands with the ringing-key, which plug is adapted to be insertedinto the line-connection terminal or jack in the act of ringing eitherof the call-bells. A double ringing-key is diagrammed. The keydesignated A is connected with and arranged to connect the alternatinggenerator and the direct-current generator or battery with theline-circuit according to the prior art for operating the cut-off relayand one of the callbells simultaneously. The key designated B isarranged to connect the alternating-current generator and source ofsteady or direct current with the line-circuit according to myinvention, the object, of course, being to actuate the cut-ofl relay andring the callbell, connected in multiple with the cut-ottrelay winding,by means of the same energizing-current. When plugz' is inserted in jackh, the tip 2' registers with line-spring 7L2 and the sleeve 2' registerswith thimble it. In the act of ringing call-bell g the key A is pressed,which distends switch-springs i i into contact with back contacts a" 6*,respectively. Under this condition of the system. circuit may be tracedfrom battery j through back contact 2", spring 2' sleeve i of plug 2',thimble h of jack h, cut-off-relay winding f to ground and back togrounded battery 1'. The current traversing the circuit of courseactuates cut ofi? relay, whereupon contact members f f disconnectline-relay and battery f and connect limbs f f of the telephone-linewith front contacts it" its, respectively. Vhen key A is in position toconnect battery j through relay f, alternatingcurrent generator j isalso connected from ground through back contact a, spring i tip 2', andline-spring-ZL? of the jack. It will be observed that under thiscondition of the line direct current will be projected over the f sideof the circuit to energize cut-off relay f while alternating current isprojected over the other side, to ring call-bell g. In this figure Ihave illustrated a practical method of operating two call-bells on aswitchboard-circuit of this character. In this particular circuit thebells may be employed for selective signaling purposes. When ringingover the circuit by means of my invention, the key B is pressed, the keyA remaining in normal posit-ion, which will maintain the cord-strandscontinuous to spring i B spring i is distended into contact with backcontact i, which contact is grounded through alternating generator andthe direct or steady current generator 7, the two generators beingconnected in series. The winding represents the primary of a suitabletransformer, which is adapted to take current from alternating generatoror any other suitable source. The winding j represents the secondary ofthe transformer, which is adapted to give alternating current suitablefor operating telephone call-bells. I/Vhen key A is in normal positionand key B is pressed for ringing, the circuit may be traced throughbattery j, secondary winding back contact a spring a spring 2' sleeve 2'of plug, thimble h" of jack h, cut-olf-relay winding f, which actuatescontact members f f and call-bell which is then connected in multiple orbridge with the cut-off relay. Under this condition of the circuitalternating and v direct current in series will traverse the circuit andenergize cut-off relay in such a manner as to draw up contact members ff and maintain them in contact with the front contacts it ifcontinuously and without flutter or vibration, as would be the case ifthe direct or steady current 7' were not connected in series withtransformer winding 1' hen contact member f is drawn up, a path forringing-current through call-bell g is pro-- On depressing key vided,the circuit being through front contact if, contact member f limb f, andcallbell winding to ground, the call-bell winding and cut-off-relaywinding being grounded in multiple and energized by the same current.

Fig. 4: is a diagrammatical representation of another well-knownswitchboard-circuit with my invention associated therewith, the

operation of the same being practically'iden call-bell m there is asupplemental call-bell m adapted to be connected in multiple or bridgewith cut-off-relay winding Z when ringing over that side of the linewith generators arranged according to my invention. When plug or isinserted into jack k and key C is pressed, the circuit is operated inthe usual manner according to the prior artc'. 0., direct current isprojected from battery 0 through back contact 92., spring n tip a ofplug n, line-spring Z0, and one of the difierential windings Z toground. The current from battery 0 operates the relay to cut outline-relay Z and difierential winding Z by drawing up armature Z whichbreaks contact at Z and makes contact at Z", this operation connectingthimblelc of the jack with the a side of the line, whereby a path foralternating current ismade over the other side of the line throughalternator 0, back contact of, spring 92 sleeve 12, of plug a, frontcontact Z contact member Z ,limb m, call-bell m with return through theearth as diagrammed When ringing over the circuit by means of myinvention,

IOO

the key D is pressed. The direct or steady 7 current andalternating-current generator in series may be traced from alternator 1through direct or steady current source r, back contact a, spring a, tip11. of plug a, line-spring this condition of the system alternating anddirect or steady current in series will energize the cut-off relaycontinuously to hold up armature Z and will also operate call-bell m",which is bridged or in multiple with differential winding Z.

I do not wish to be limited to the precise circuits and systems hereindescribed, as my invention may be employed with any combination ofcircuits wherein it is necessary to operate simultaneously a direct orsteady current type of relay and a suitable call-bell in multiple; but,i r

Having described my invention, what '1' claim as new, and desire tosecure by Letters Patent, is-

1. In a telephone system, the combination of a line, a relay bridgedwith the line and a high-resistance call-bell bridged with the line andin multiple with the relay, and a source of suitable current to actuatethe relay in series with a source of suitable current to actuate thehigh-resistance call-bell, and. means to connect the two sources ofcurrent in multiple with the call-bell and relay in the act ofenergizing the relay and call-bell simultaneously, substantially asdescribed.

2. In a telephone system, the combination of a line, a direct-currenttype of relay and a polarized call-bell bridged with the line, and meansto project suitable current over the line to actuate the bell and relaysimultaneously, and means consisting of a suitable source of current toactuate the relay, and a suitable source of current to actuate thecallbell, the two sources of current being connected in series with eachother and in multiple with the call-bell and relay during the operationof the two elements, substantially as described.

3. In a telephone system, the combination of a line, a direct-currenttype of relay and a high resistance polarized call -bell bridged withthe line, and means to actuate the relay and call-bell simultaneously inthe act of ringing the call-bell, the means comprising asuitable sourceof current to actuate the relay, and a suitable source of current toactuate the call-bell, the two sources of current being connected inseries with each other and in multiple with the call-bell and relay inthe act of ringing the call-bell, substantially as described.

4. In a telephone system, the combination of a line, a polarizedcall-bell bridged with the line and a high resistance in the call-bellcircuit, a direct-current type of relay bridged with the line andadapted to be operated when the call-bell is rung, and means to actuatethe call-bell and relay in multiple in the use of the line, the meanscomprising a suitable source of current to actuate the polarizedcallbell, and a suitable source of current to actuate the relay, the twosources of current being connected in series with each other and inmultiple with the call-bell and relay in the use of the line,substantially as described.

5. In a telephone system, the combination of a line, a polarizedcall-bell connected with the line and a condenser in the call-bellcircuit, a direct-current type of relay bridged with the line and inmultiple with the callbell and adapted to be operated when the callbellis rung, and means to actuate the call-bell and relay in multiple in theuse of the line, the means comprising a suitable source of current toactuate the polarized call-bell, and a suitable source of current toactuate the relay, the two sources of current being connected in serieswith each other and in multiple with the call-bell and relay in the useof the line, substantially as described.

6. In a telephone system, the combination with a line-circuit, of aline-signal therefor, a cut-off relay bridged between said line-circuitand ground and. adapted when actuated to render the line-signalinoperative, an alternating-current call-bell bridged between saidline-circuit and ground and adapted to be ac tuated in multiple withsaid cut-ofi' relay, a cord-circuit to establish connection with theline-circuit, an alternating-current generator in the cord-circuit andadapted to be bridged with the call-bell and cut-off relay to actuateboth of said elements, and a source of steady current connected inseries with the alternating-current generator to maintain the cut-offrelay actuated while the alternating ringing-current is reversing,substantially as described.

7. In a telephone system, the combination of 'a line, a polarizedcall-bell bridged with the line and means in the bell-circuit to preventexcessive current from passing therethrough, a relay in a bridgedcircuit with the line and adapted to be acted upon by theringing-current, a source of alternating current bridged with the lineto actuate the call-bell and relay, and a source of direct current inseries with the alternating current to energize the relay while thealternating current is reversing, substantially as described.

8. In a telephone system, the combination of a line, a call-bell bridgedwith the line and a high resistance in the call-bell circuit, a relaybridged with the line, and a source of alternating current bridged withthe line to actuate the call-bell and relay in multiple, and a source ofdirect current in series with the alternating current to energize therelay while the alternating current is reversing, substantially asdescribed.

9. In a telephone system, the combination with a line, of a call-bellbridged with the line and a condenser in the call-bell circuit, a relaybridged with the line and in multiple with the call-bell, and a sourceof alternating current bridged with the line to actuate the call-belland relay in multiple in the use of the line, and a source of directcurrent in series with the alternating current to energize the relaywhile the alternating current is reversing, substantially as described.

10. In a telephone system, the combination of a line, a polarizedcall-bell bridged with the line and means in the bell-circuit to preventexcessive current passing therethrough, a relay in a bridged circuitwith the line and adapted to be acted upon by the ringing-current, asource of alternating current bridged with the line to energize thecall-bell and relay in multiple in the use of the line, and a source ofdirect current in series with the alternating current to energize therelay when the alternating current is m'Z, substantially as described.

11. In a telephone system, the combination with a line, of a call-bellbridged with the line and means in the bell-circuit to prevent excessivecurrent from interfering with the bells operation, a directcurrent typeof relay bridged with the line, and means to connect a suitable currentfor operating the relay and a suitable current for operating thecall-bell in series and bridge the same with the line in the use of theline, whereby the call-bell and relay will be operated in multiple,substantially as described.

12. In a telephone system, the combination with a line, of a call-bellbridged with the line and means in the call-bell circuit to preventexcessive current from interfering with the bells operation, adirect-current type of relay bridged with the line and in multiple withthe call-bell, a source of alternating current bridged with the line toactuate the call-bell with the line, a relay bridged with the line,-

and a source of non continuous potential bridged with the line to chargeand discharge the condenser through the call-bell, and a source ofdirect current in series with the non-continuous potential to maintaincurrent through the relay when the non-continuous potential isinoperative on the relay, substantially as described.

14:. In a telephone system, the combination of a subscribers line, and acut-off relay for the line, a call-bell at the subscribers stationconnected with the line and means in the callbell circuit to preventexcessive current from interfering with the bells operation, a suitablesource of current for operatingthe callbell and asuitablesource ofcurrent for oper-- ating the relay connected in series with each otherand adapted to be bridged with the callbell and relay in the act ofringing the callbell, substantially as described.

15. In a telephone system, the combination of a subscribers line, and acut-ofl relay bridged with the line, a polarized call-bell at bridgedwith the line, a polarized call-bell bridged with the line at thesubscribers station, and means in the call-bell circuit to preventexcessive current from interfering with the bells operation, a source ofalternating current bridged with the line for operating the call-belland relay in multiple in the use of the line,'and a source of directcurrent in series with the alternating-current source to hold up thecut-off relays armature while the alternating current is reversing,substantiallyas described.

17. In a telephone system, the combination with a subscribers line, of acut-01f relay for the line, a polarized call-bell at thesubscribersstation and a condenser in the call-bell, circuit, means toproject suitable current over the line to actuate the call-bell andrelay in multiple simultaneously, the means comprising a source ofdirect current in series with a source of fluctuating current,substantially, as described.

18. In a telephone system, the combination with a subscribers line, of adirect-current type of cut-off relay connected with the line, apolarized call-bell at the subscribers station and a high resistance inthe call-bell circuit to prevent excessive current from interfering withthe bells operation, a source of direct current in series with a sourceof fluctuating current and means to connect the same in mul; tiple withthe call-bell and cut-off relay in the use of the line, whereby the callis rung and the cut-off relays armature prevented from fluttering,substantially as described.

19. In a telephone system, the combination with a subscribers line, of adirect-current type of cut-off relay connected with the line, a high-resistance polarized call-bell at the subscribers station, a sourceof direct current in series with a source of fluctuating current and.means to connect the same in multiple with the call-bell and cut-offrelay in the use of the. line, whereby the call-bell is rung and thecutoff relays armature prevented from fluttering, substantially asdescribed.

- 20. In a telephone system, the combination with a telephone-lineextending to a subscribers station, of a cut-off relay grounded from oneside of the circuit, a call-bell grounded from the same side of thecircuit and in parallel with the cut-off-relay winding, and means in thecall-bell circuit to prevent excessive current from interfering with thebells operation, a suitable source of current to operate the call-belland a suitable source of current to operate the cut-off relay, the twosources of current being connected in series with each other and bridgedwith the cut-off relay and call-bell, whereby the call-bell is rung andthe cut-off relays armature prevented from fluttering in the act ofcalling the subscriber, substantially as described.

21. In a telephone system, the combination with a telephone-lineextending in two limbs to a subscribers station, of a direct-currenttype of cut-ofi relay grounded from one limb of the line, a polarizedcall-bell grounded from the same limb of the line and in multiple withthe cut-oif-relay winding, and means in the call-bell circuit to preventexcessive current from interfering with the bells operation, a source ofalternating current bridged with the line to actuate the call-bell andcut-off relay in multiple in the use of the line, and a source of directcurrent in series with the alternating current to energize the cut-offrelay while the alternating current is reversing, substantially asdescribed.

22. The combination with a telephone-line and a connection-terminal forthe line normally disconnected therefrom, of a relay for connecting theconnection-terminal with the line, a high-resistance polarized call-bellbridged with the line and adapted to be connected in multiple with therelay in the use of the line, a source of alternating current adapted tobe connected with the connection-terminal for operating the call-belland relay in multiple in the use of the line, and a source of directcurrent in series with the alternating-current source to hold up therelays armature while the alternating current is reversing,substantially as described.

23. The combination with a te1ephone-line and a connection-terminalforthe line normally disconnected therefrom, of a relay for connectingthe connection-terminal with the line when the relay is energized, apolarized callbell connected with the line and in multiple with therelay-winding in the use of the line, and means in the call-bell circuitto prevent excessive current from interfering with the bells operation,means connected with the connection-terminal to actuate the call-belland relay simultaneously, the means consisting of a suitable source ofcurrent to actuate the relay, and a suitable source of current toactuate the call-bell, the two sources of current being connected inseries with each other and in multiple with the call-bell and relay inthe use of the line, substantially as described.

24. The combination with a telephone-line having a limb extending to acentral office, of a line-contact for said line normally disconnectedtherefrom, a call-bell and condenser in series with said telephone-line,a cord-circuit and connection-plug, a relay to automatically connect theline-contact with said line and the call-bell and condenser in multiplewith the relay, means included in said cordcircuit to actuate said relayand call-bell in multiple simultaneously, said means comprising a sourceof direct current in series with a source of fluctuating current,substantially as described.

25. The combination with a telephone-line and a connection-terminaltherefor normally disconnected therefrom, of a relay for connecting theconnection-terminal with the line, a call-bell and condenser bridgedwith the line and adapted to be connected in multiple with the relaywhen the relay is energized, a source of non-continuous potentialconnected with the connection-terminal to energize the relay andcall-bell simultaneously, and a source of current in series with thenon-continuous potential to maintain said relay energized while thenon-continuous potential is inoperative on the relay, substantially asdescribed.

26. In a telephone system, the combination of a subscribers line, acut-off relay for the line, a call-bell and condenser at the subscribersstation, means to connect the cut-off relay in multiple with thecall-bell and condenser, a source of non-continuous potential bridgedwith the line to actuate the relay and charge and discharge thecondenser through the call-bell, and a source of current in series withthe non-continuous potential to maintain current through the cut-offrelay when the non-continuous potential is inoperative on the cut-ofirelay, substantially as described.

In witness whereof I have hereunto subscribed my name in the presence oftwo witnesses.

THOMAS C. DRAKE.

Vitnesses:

VERNON DURBIN, E. J. ARRICK.

